Compound duplex pumping-engine.



No. 777,495. PATENTED DEC. 13, 1904. A. F. OAVANAUG-H.

COMPOUND DUPLEX PUMPING ENGINE.

APPLIOATION FILED oar. 21, 1903. N0 MODEL.

INVENTOR 5 MAW $fiwvwxmwgm ATTORNEY Patented December 13, 1904-.

PATENT OFFICE.

ANDREW F. CAVANAUG-H, OF MILWVAUKEE, VISGONSIN.

OQWIPOUND DUPLEX PUlVlFlNG-ENGlNEn SPECIFICATION forming part of LettersPatent No. 777,495, dated December 13, 1904.

Application filed October 21, 1908. Serial No. 177,941. (No model.)

To all whom it TIMI/y concern.-

Be it known that 1, ANDREW F. UAvANAUou, a citizen of the United States,residing at Milwaukee, in the county o'l Milwaukee and State ofWVisconsin, have invented certain new and useful Improvements inCompound Duplex Pumping-Engines, of which the following is aspecification.

My invention relates to improvements in direct-acting duplexpumping-engines of the compound type; and my object is to providecertain novel relative arrangements oi? the steam-cylinders,slide-valves, and valve-gearing whereby an efficient engine of this typemay be produced in a compact form.

I attain my object by means of the arrangement and construction of theseveral parts relatively to one another substantially in the mannerillustrated in the accompanying draw ings, in Which Figure 1 representsa side elevation of a pumping-engine involving my improvements, theleft-hand cylinders being shown in section on the line no a: in Fig. 2;and Fig. 2 represents a cross-section on the line 1 y in Fig. 1 whenlooking in the direction of the steamcylinders, the cross-heads beingleft out.

Like letters refer to like parts in the two views.

A and B represent, respectively, the high and low pressure cylinders onthe left-hand side as the engine is viewed in Fig. 2, and G and D therighthand high and low pressure cylinders. respectively. These high andlow pressure cylinders are placed directly one above the other, with thevalve-chests E E for the high-pressure cylinders at the top and thevalve-chests F F for the low-pressure cylinders between the high and lowpressure cylinders. Steam is admitted to the valve-chests E by a crossconnection G, coupled to the steam-supply pipe, and the exhaust is takenfrom the valve-chests F by way of a cross connection H, coupled to theexhaust-pipe. In

thehigh-pressure valve-chests I provide slidevalves 1 and in thelow-pressure valve-chests piston-valvesJ. From the slide-valves ll: rodsK lead out through suitable striding-boxes to links L, which are coupledto the valve-operating gear hereinafter to be described, and

the valve-rods M, which actuate the pistonvalyes J, are coupled to saidgearing by links N. The higl'i-pressure pistons O are connected bypiston-rods P to cross-heads Q, which reciprocate in-suitable guidesprovided in the upper portion of the engine-frame. These cross-heads Qare connected by links it to rockarms S, one on each side of the engine,and the low-pressure pistons are connected with said rock-arms S throughpiston-rods U, crossheads V, and links W. The piston'rods U for thelow-pressure pistons are preferably double and are connected together atX by a yoke, to which is attached the rod Y, which actuates the plungerfor the pump, (not shown,) this rod Y passing through a striding-boxwhere the engine-frame at Z is attached in the usual manner to thepump-cylinders.

The valve-operating gear comprises a series of crank-arms andcross-shafts as follows: At the left-hand side of the engine a longcrankarm a actuates a shaft s, which in turn actuates a short crank-armb, coupled to the link L, which actuates the high-pressure slidevalve onthe right'rhand side of the engine. The shorter crank-arm 0, attached toshalt t, actuates, through the short crank (Z, the link N, whichactuates the low-pressure valve for the right-hand cylinders. Thesecrank-arms a c are coupled to the lelt-hand cross-head V by links ICrank-arms (2 and 1/, coupled by similar links to the right-handcross-head V, actuate, through shafts a and o, the short crank-armsf It,coupled to the valves which actuate the left-hand pair of high and lowpressure cylinders.

In my valve-motion .I make provision for permitting the valves to restfor a short period of time at the end of their travel in each directionwhile the crank-arms are making their initial movements on eachforward-andback swing in order to give time for the proper admission andexhaust of the steam to and from the cylinders. To accomplish this, 1provide the links L and N with slotted ends, in which are fittedslide-blocks 2', carried by the crank-pins. These slide-blocks areprovided with adjustable tappets Ii: at each end, by means oi which thethrow of the valves is adjusted. in order that the piston-valves J mayremain stationary while the tappets are out of engagement with the endsof the slots in links N, they must be in balance within the valve-chestsF, and to attain this balance I preferably make said valves hollow andarrange the ports and passages as represented in Fig. 1, the ports 0 andp from the highpressure cylinders leading to grooves j and j, formed ateach end of the valve between suitable packing-rings, and the ports (7and 9", leading to the low-pressure cylinders, being so positioned as tobe placed in communication, respectively, with the ports 0 and p by wayof the grooves j and or with the exhaust H by Way of the central groovej as the valve is moved to one end or the other of its travel.

In operation, steam being admitted to the valve-chest E by way of theconnection Gr, if the piston in the right-hand high-pressure cylinder bemoved forward or in the direction of the pump the low-pressure piston onthe right-hand side will be moved toward the rear or away from the pumpby reason of the rock-arm connection between the piston-rods P and U onthat side. As the right-hand cross-head V is thus moved to the rear oraway from the pump the motion transmitted thereby to crank-arm 6 willtransmit a rearward movement to crank arm f, thereby throwing theslide-valve I for the left-hand high-pressure cylinder A to the rear andadmitting steam to the forward end of that cylinder through port 12which will throw the piston O therein to the rear. At the same timecrank-arm Q will transmit a forward movement to crank-arm it, therebythrowing piston-valve J for the left-hand cylinder B forward, wherebythe exl1aust-steam from the cylinder A will be admitted through port 0,around the groot e j in valve J, and through port q to the rear of thepiston T, throwing said piston forward. The exhaust from in front ofpiston T passes out through port '7 and groove ,7' to outlet H. Therearward motion of the piston 0 will be transmitted through link R,rock-arm S, and link W to assist the forward motion of cross-head V,transmitted thereto by piston-rods U as the piston T moves forward. Asthe cross-head V for the right-hand cylinders A and B moves forwardtoward the pump, motion will be transmitted, through the crank-arms aand c, to the crank-arms I) (Z, which are coupled to the rods for thehigh and low pressure slidevalves I and J for the right-hand cylinders,and said valves will be thrown, the valve 1 rearward and the valve Jforward, whereby the piston in high-pressure cylinder C will be thrownto the rear and the piston in lowpressure cylinder D will be thrownforward. This forward motion of the piston inlowpressure cylinder D willthrow the crankarms a and '9 forward, thereby reversing the slide-valvesfor the high and low pressure cylinders A and B on the left-hand sideand reversing the strokes of the pistons therein, admission to cylinderA then taking place through port m and the steam passing from cylinder Ato cylinder B through ports p and 0' by way of groove j on valve J.Exhaust from cylinder B now passes from port q to outlet H by way ofgroove j on said valve.

It will be noted that the exhaust-ports 0 and p in the high-pressurecylinders are located at some little distance from the ends of thecylinders, whereby the pistonsin said cylinders as they approach theends of their stroke in either direction will cut off the exhaust,thereby forming a steam-cushion which will bring said pistons to a stopbefore they can strike the cylinder-heads. As all the working parts willbe brought to a standstill at the same time, it will be seen that thelowpressure pistons will also be prevented from striking theircylinder-heads. This arrangement, it will be seen, provides a compactassemblage of the cylinders, valvechests, and valve-gearing, thepressure exerted on the high-pressure pistons being transmitted to thecross-heads for the low-pressure piston-rods by way of the links R andWV and the rock-arms S.

While I have described my preferred Way of coupling together the pistonson one side, with the valve-motions on the other side, I do not wish tobe confined strictly to this particular arrangement, as it will be plainthat the valves of one set of cylinders can be operated by any movingpart or parts which are actuated by steam in the other set of cylindersthat is to say, instead of connecting the valvemotion arms to thecross-heads by links, as shown, I may operate the valve-motion arms forone set of cylinders by connecting them to or actuating them by anyother moving part or parts actuated by the steam in the other set ofcylinders.

Having thus described my improvements, what I claim as my invention, anddesire to secure by Letters Patent, is

1. In ahorizontal compound duplex pumping-engine, the combination of twopairs of high and low pressure cylinders set side by side, each paircomprising a high-pressure cylinder and a low-pressure cylinder oneabove the other, ports and passages leading from the one to the otherand to the exhaust, a valve to control the passage of steamtherethrough, a main valve to control the admission to the high-pressurecylinder, pistons in each pair of cylinders traveling in oppositedirections, a connection between the members of each pair of pistonswhereby motion is transmitted from one to the other and to apumpplunger, and a valve-gear comprising two pairs of cross shaftshaving crank arms at each end, the crank-arms at the right-hand side ofone pair of cross-shafts being actuated by the right-hand pistons, thecrankarms on the lett-hand side of said pair of cross-shafts beingcoupled to the valves for the left-hand pair of cylinders, and thecrankarms on the other pair of cross-shafts being actuated in likemanner on one side by the left-hand pistons and on the other side beingcoupled to the right-hand valves, whereby the valves are actuated intheir proper relative directions to change the piston-strokes.

2. In a horizontal compound duplex pumping-engine, a valve-gearcomprising two pairs of cross-shafts having crank-arms at each end, thecrank-arms at the right-hand side oi one pair of cross-shafts beingcoupled to a moving part actuated by the right-hand pistons, thecrank-arms on the left-hand side oi said pair of cross-shafts beingcoupled to the valves for the left-hand cylinders, and the crankarms onthe other pair of cross-shafts being connected in like manner on oneside with a moving part actuated by the left-hand pistons and on theother side being coupled to v the right-hand valves, the couplingsbetween the crank-arms and valves comprising links pivotally connectedto the valve-rods at one end and slotted at the other end, slide-blockson the crank-pins engaging said slots, and tappets at each end of theslide-bloeks-to strike the ends. of said slots, whereby the valves areactuated intermittently in their proper relative directions to changethe piston-strokes.

3. In a horizontal compound duplex pumping-engine, the combination oftwo pail-sot high and low pressure cylinders set side by side, each paircomprising a high-pressure cylinder and a low-pressure cylinder oneabove the other, ports and passages leading from the one to the otherand to the exhaust, a

valve to control the passage of steam therethrough, a valve to controlthe admission to the higlrpressure cylinder, cross-heads attached to thepiston-rods for both high and low pressure cylinders and reciprocatingin guides in the engine-frame, rock-arms carried by said frame in linewith each pair ol cylinders, connecting-rods between said rock-arms andthe cross-heads whereby motion of the high-pressure pistons istransmitted. to the low-pres sure pistons, a pump-plunger in directconnection with one piston-rod oi each pair, and a valve-gear comprisingtwo pairs oi crossshalits having crank-arms at each end, the crank-armsat the right-hand side of one pair of cross-shafts being coupled to oneof the cross-heads on the same side, the crank-arms on the left-handside of said pair of crossshat'ts being coupled to the valves For thelefthand pair of cylinders, and the crank-arms on the other pair ofcross-shafts being coupled in like manner on one side to a left-handcrosshead and on the other side to the right-hand valves, the couplingsbetween the crankarms and valves comprising links pivotally connected tothe valve-rods at one end and slotted at the other end, slide-blocks onthe crankpins engaging said slots, and a tappet at each end of theslide-blocks to strike the ends of said slots, whereby the valves areactuated intermittently in their proper relative directions to changethe piston-strokes.

In testimony whereof l have allixed my signature in presence of twowitnesses.

ANDREYV 11. (JAVANAUGH. Witnesses:

SAML. W RIGHT, Anoririi U. (Jinan.

